Stress Test May Reveal a Man's Heart Risk
Study Clarifies Value of Stress Testing in Men's Heart Health
Sept. 27, 2004 -- The exercise stress test is a useful screening tool for people with significant coronary artery disease. Now a major study say this test can also help predict future heart attacks in people with multiple risk factors even if they don't have heart disease.
Researchers with the Framingham Heart Study report that among symptom-free men with several risk factors for heart disease, poor performance on an exercise treadmill test more than doubled the risk of a heart attack and other coronary artery events. The study also showed that exercise testing was of little or no value in people at low risk of future heart attacks.
Six days ago, researchers from The Cleveland Clinic reported similar findings in people without symptoms. The group they studied were said to be at high risk for heart disease using a risk assessment scoring system different from the one used in the Framingham study.
"The conclusions from these studies are remarkably similar," Framingham researcher Gary J. Balady, MD, tells WebMD. "Both studies suggest that exercise testing is of little benefit in low-risk men who are asymptomatic and that the risk for asymptomatic, high-risk men who perform poorly on an exercise stress test may be even higher than we have thought."
The newly released study, to be published in the Oct. 5 issue of the American Heart Association journal Circulation, included 1,431 men and 1,612 women.
Researchers calculated a 10-year heart disease risk for all participants using the Framingham Risk Score. This assigns a point value to risk factors such as high blood pressure, total cholesterol, HDL cholesterol, age, diabetes, and smoking history. A person's total score is used to predict the risk of heart attack or chest pain over the following decade.
People with a risk score of 9% or less are considered at low risk for such events, while those with a score of 20% or more are considered at high risk.
The average age of the study participants was 45, and all were followed for roughly 18 years after having an exercise stress test. During follow-up, 225 men (16%) and 81 women (5%) experienced a coronary event such as heart disease-related death, chest pains, or heart attack.
Performing poorly on the exercise stress test strongly predicted a future heart event among men with the highest scores.
Balady says high-risk men who fail to achieve a target heart rate on a treadmill test or perform poorly by other measures should receive the most aggressive preventive treatments available, including blood pressure and cholesterol-lowering medications. They may also be candidates for more specific diagnostic testing, such as imaging stress tests or angiography.
The findings also suggest that regular exercise can lower heart disease risk no matter what a person's other risk factors are. Men who were able to exercise longer and more intensely had a lower risk of heart events, even among those men considered to be at high risk.
"It does appear that being fitter lowers risk, even among high-risk individuals," Balady says.